The Training Core will provide support for three post-doctoral fellows who will complete a two year period of cross-training. The training program is designed to provided research experienced in a multi- disciplinary, academic setting. When completed,, it will permit the trainee to be more effective and productive when participating in multi- disciplinary research teams engaged in reducing exposure and risk to hazardous environmental chemicals. The program will consist of the trainee participating in two different research laboratories within the Program Project (one biomedical and one non-biomedical) over a two- year period. The laboratories involved will be engaged in a collaborative research effort in which the trainee will be a participant. In addition, the trainee will have the opportunity to engage in didactic coursework in the area in which they have not concentrated in their prior Ph.D. degree program or work experience. This will allow the trainee to rapidly attain the information needed to participate in research in a discipline that is new to him or her. Attendance at a specified minimum of seminars at a national meetings will augment the cross-training experience. The universities involved in providing the training have excellent research facilities and education programs in toxicology, environmental engineering, microbiology chemistry, soil science and other disciplines. The combination of required facilities and an excellent research faculty will help produce well trained individuals who will meet the national need for scientists who are knowledgeable and experienced in working within multi-disciplinary teams solving complex environmental problems.